MY350Z.COM - Nissan 350Z and 370Z Forum Discussion - Brakes & Suspension

Knocking sound right rear passenger side fender weld

SwampFox — Fri, 08 May 2026 14:23:07 GMT

So I seen a few posts on this and read them but they don't seem to fit mine just right like "yea that's it" so I recently bought a 03 350z base model Stick 6speed and I'm loving the car coming over from Ls cars it's new and fun but when I bought the car it has its issues well first week I bought it drove it all week adjusted to it going nice second week I took it to the drag strip (dumbass) mistake #1 found out the car had a welded diff it showed no signs of one when I had bought it tires didn't skid on turns didn't sway on curves but anyways first pull on track went great ran a low 8 @80mph wasn't bad second pull I heard a clink sound from the rear passenger fender weld **** my self cause it was Loud got to the end check on the suspension every looked fine yanked on the tire trying to move it nothing seemed broken or loose drove it home that night 40 min drive 20 mins into the drive I hear a knocking sound it's not loud but it sounds like someone's knocking on your door repeatedly non stop it's not like loud but you can hear it and you know it's there well nwxt morning let the car warm up and drove just fine knocking was still there but it was fine till I got on the highway soon as I went from 4th to 5th gear and accelerated the car started to sway and I mean bad to where I let go till she caught herself and straightens back out but if I slow accelerated it doesn't so it as bad but if I try to hit it it sways back and forth I've asked friends who own a few they tell me I have a bad Axel or the bearings are shot or the control arms about to give but when I checked it again this time jacked up everything seems in order nothings loose or missing is this just a normal thing is the welded diff causing the swaying on hard acceleration if it is why does it really only do it in 5th and 6th gear from what I read on other posts everyone says an alignment or just ignore it but I don't like knowing something's wrong and when it finally goes it causes more issues then to begin with ill try to get a video of it knocking and a few pic of the suspension when I get off work

Need new bushings

Capn Al — Tue, 05 May 2026 15:46:17 GMT

Hi Everyone, Brand new to the forum, 2006 roadster enthusiast. 121K miles. I would be happy with stock style bushings. Is there a supplier that sells a complete kit? Some bushings need some love and all of the boots are cracked. What can be done as ECONOMICALLY as possible? Appreciate any help and advice. I would probably do the job myself and I don't have a lift available.

Custom Designed Coilover Kit

Rc_velox — Wed, 29 Apr 2026 00:50:24 GMT

Hey everyone, I've designed my own coilover kit using the Bilstein AS2 line of parts as its basis.

Here's a image of the front and rear designs in CAD:

Here are some shots of the machined parts before installation:

Here's a picture of the shock dyno and assembly:

Installed in the car:

Images of the shock dyno graphs:

I went with 700 lb/in front and 375 lb/in rear spring rates (12.5 kg/mm front, 6.7 kg/mm rear). The rear is installed as true rear. I calculated an approximate damper curve for those spring rates and matched the real life builds to those theoretical curves. The Bilstein AS2 shaft I used has an "open" adjuster, so it adjusts both compression and rebound simultaneously (single open hole).

So far I've put about 1k miles on the parts and I'm quite happy so far. The ride is very firm, but not harsh at all, and the handling is definitely sharper with those spring rates. My plan is to turn this car primarily into a track day/weekend mountain car, and this coilover kit is a good step in that direction.

I'm reaching out to the 350z community to see if anyone would be interested in a kit like this... I can order these parts and custom build a kit for anyone. Also, Bilstein shock parts fit inside BC Racing shock bodies, so I can also build these damper curves into an existing BC Racing unit if anyone wants a retrofitted kit.

Feel free to reach out with questions and comments. Thanks for reading!